Downhole tool for controlling the drilling course of a borehole
First Claim
1. A downhole tool adapted to be connected to a drill string by a connection atop the tool, the tool comprising:
- a mandrel for connection with the drill string;
a body, the mandrel being rotatable within the body;
a plurality of blades individually extendible radially from the body to engage the wall of a well bore, the radial position of the blades being adjustable between a first retracted position and a second extended position, to position a centreline of the mandrel at a desired position relative to a longitudinal axis of the well bore;
a positioning system for holding each of the blades at the retracted position, at the extended position or at any intermediate position between the retracted and extended positions;
a control unit for controlling the positioning system, the control unit being operable to maintain the blades in engagement with the wall of the well bore and the centreline of the mandrel at a desired position relative to the centreline of the well bore as the drill string advances during a drilling operation regardless of variations in the well bore diameter; and
an energizing source;
wherein at least two of the blades are locked at a given extension, with the remaining blades communicably connected to the energizing source, thus allowing those energized blades to remain in contact with the well bore when compensating for variations in the nominal diameter of the well bore.
5 Assignments
0 Petitions
Accused Products
Abstract
A downhole tool connectable to a drill string by a connection atop the tool includes a mandrel for connection with the drill string, the mandrel being rotatable within a body. A plurality of blades are individually extendible radially from the body to engage the wall of a well bore, the radial position of the blades being adjustable between a first retracted position and a second extended position to position the centre line of the mandrel at a desired position relative to the longitudinal axis of the well bore. A positioning system is provided to hold each of the blades at the retracted position, the extended position or at any intermediate position therebetween.
143 Citations
21 Claims
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1. A downhole tool adapted to be connected to a drill string by a connection atop the tool, the tool comprising:
- a mandrel for connection with the drill string;
a body, the mandrel being rotatable within the body;
a plurality of blades individually extendible radially from the body to engage the wall of a well bore, the radial position of the blades being adjustable between a first retracted position and a second extended position, to position a centreline of the mandrel at a desired position relative to a longitudinal axis of the well bore;
a positioning system for holding each of the blades at the retracted position, at the extended position or at any intermediate position between the retracted and extended positions;
a control unit for controlling the positioning system, the control unit being operable to maintain the blades in engagement with the wall of the well bore and the centreline of the mandrel at a desired position relative to the centreline of the well bore as the drill string advances during a drilling operation regardless of variations in the well bore diameter; and
an energizing source;
wherein at least two of the blades are locked at a given extension, with the remaining blades communicably connected to the energizing source, thus allowing those energized blades to remain in contact with the well bore when compensating for variations in the nominal diameter of the well bore. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16)
- a mandrel for connection with the drill string;
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17. A downhole tool adapted to be connected to a drill string by a connection atop the tool, the tool comprising:
- a mandrel for connection with the drill string;
a body, the mandrel being rotatable within the body;
a plurality of blades individually extendible radially from the body to engage the wall of a well bore, the radial position of the blades being adjustable between a first retracted position and a second extended position, to position a centreline of the mandrel at a desired position relative to a longitudinal axis of the well bore;
a positioning system for holding each of the blades at the retracted position, at the extended position or at any intermediate position between the retracted and extended positions; and
a control unit for controlling the positioning system, the control unit being programmable when the tool is down a well bore by means of coded signals sent from the surface and operable to maintain the blades in engagement with the wall of the well bore and the centreline of the mandrel at a desired position relative to the centreline of the well bore as the drill string advances during a drilling operation regardless of variations in the well bore diameter, said control unit incorporates a gravity sensor to establish orientation of the body of the tool.
- a mandrel for connection with the drill string;
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18. A downhole tool adapted to be connected to a drill string by a connection atop the tool, the tool comprising:
- a mandrel for connection with the drill string;
a body, the mandrel being rotatable within the body;
a plurality of blades individually extendible radially from the body to engage the wall of a well bore, the radial position of the blades being adjustable between a first retracted position and a second extended position, to position a centreline of the mandrel at a desired position relative to a longitudinal axis of the well bore;
a positioning system for holding each of the blades at the retracted position, at the extended position or at any intermediate position between the retracted and extended positions; and
a control unit for controlling the positioning system, the control unit being operable to maintain the blades in engagement with the wall of the well bore and the centreline of the mandrel at a desired position relative to the centreline of the well bore as the drill string advances during a drilling operation regardless of variations in the well bore diameter, said control unit including a timer.
- a mandrel for connection with the drill string;
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19. A downhole tool adapted to be connected to a drill string by a connection atop the tool, the tool comprising:
- a mandrel for connection with the drill string;
a body, the mandrel being rotatable within the body;
a plurality of blades individually extendible radially from the body to engage the wall of a well bore, the radial position of the blades being adjustable between a first retracted position and a second extended position, to position a centreline of the mandrel at a desired position relative to a longitudinal axis of the well bore;
a positioning system for holding each of the blades at the retracted position, at the extended position or at any intermediate position between the retracted and extended positions; and
a control unit for controlling the positioning system, the control unit being operable to maintain the blades in engagement with the wall of the well bore and the centreline of the mandrel at a desired position relative to the centreline of the well bore as the drill string advances during a drilling operation regardless of variations in the well bore diameter;
wherein blade extensions are used to log the volume of the bore as the tool travels in and out of the borehole. - View Dependent Claims (20)
- a mandrel for connection with the drill string;
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21. A downhole tool adapted to be connected to a drill string by a connection atop the tool, the tool comprising:
- a mandrel for connection with the drill string;
a body, the mandrel being rotatable within the body;
a plurality of blades individually extendible radially from the body to engage the wall of a well bore, the radial position of the blades being adjustable between a first retracted position and a second extended position, to position a centreline of the mandrel at a desired position relative to a longitudinal axis of the well bore;
a positioning system for holding each of the blades at the retracted position, at the extended position or at any intermediate position between the retracted and extended positions;
a control unit for controlling the positioning system, the control unit being operable to maintain the blades in engagement with the wall of the well bore and the centreline of the mandrel at a desired position relative to the centreline of the well bore as the drill string advances during a drilling operation regardless of variations in the well bore diameter; and
an energizing source;
wherein the blades on a gravitational low side of the hole are locked at a given extension, with the uppermost blade or blades communicably connected to the energizing source, thus allowing those energized blades to remain in contact with the well bore when compensating for variations in the nominal diameter of the well bore.
- a mandrel for connection with the drill string;
Specification